Numan Haider Was Summoned to Police Station Over Reports He Waved Islamic State Flag

CANBERRA, Australia—Australian police say they are trying to learn more about the people who were associating with a terror suspect in the hours and days before he was shot dead by police on Tuesday.

The 18-year-old man, identified by authorities as Numan Haider, was killed Tuesday evening after he was summoned to a police station in Melbourne to discuss reports he'd been waving an Islamic State flag at a local shopping mall.